Computer numerical controlled (CNC) positioning systems have enabled significant changes in manufacturing technology over the last several decades. Initially CNC technology was used to provide tool positioning and spindle speed control for milling machines to enable a high degree of repeatability. Nearly every manufacturing process since has had CNC technology incorporated to some degree. Recently CNC technology has been adapted for use in emerging additive manufacturing technologies.
Recently, three-dimensional (3D) printing technology has emerged as a paradigm shift to traditional manufacturing. 3D printing is an additive technology in which objects are created through sequential layering, using inkjet-like nozzles to dispense the object material. Traditional manufacturing is subtractive, and involves cutting, etching, and removal of material. In both cases, a CNC-controlled tool is positioned to add or remove material to create a final product.
3D printing employs software to model the object to be produced, slice the model into digital cross-sections, and use the cross-sections as guides to print the object. The printing or lying down of material involves liquid, powder, or layers of sheets. Because of the precision and scale of the 3D printer, almost any shape can be manufactured using the technology.